Hold down and return clip and adjusting screw assembly for pivoted lever clutches



United States Patent [72] Inventor Martin .I. llermns Fort Wayne.Indiana [2! 5 Appl No. 753,971 [22] Filed Aug. 20, 1968 (45) PatentedNov. 10, 1970 [73] Assignee Dane Corporation Toledo, Ohio a corporationof Virginia [54 HOLD DOWN AND RETURN CLIP AND ADJUSTING SCREW ASSEMBLYFOR PIVOTED LEVER CLUTCIIES 4 Claims, 4 Drawing Flgl.

[52] U.S.Cl. .1 i 192/99, 192/703: 267/53 [5i] lnt.Cl i i i Fl6d13/54[50] Field ofSeareh. 192/99'(A).

[56] References Cited UNITED STATES PATENTS 2, 24,475 11/1955 Thelander192/99( A LX 3.276.555 10/1966 Phelps eta] 192/99(AX)LX PrimaryExaminer! Benjamin W Wyche lll Attorney-Walter E Pavlick. Harold D.Shall, Richardson B.

Farley and John F. Teigland ABSTRACT: A spring loaded clutch havingrelease levers is rovided with a novel spring clip and adjusting screwassembly so as to yield an easily manufactured assembly which issecurely held together yet capable of easy disassembly. The adjustingscrew is mounted on the pressure plate and includes a shouldered portionso that the spring clip attached to it is securely mounted with it. Thespring clip, itself, has a benttab portion which engages the clutchlever end and has -onnected and integral therewith an L-shaped portion,one leg of the L having an open slot leading to a slightly enlargedbore. The spring clip may thereby be assembled easily on the adjustmgscrew by sliding the clip over the shank portion of the adiustmg screwand then permitting it to move outwardly so that the spring clip boreportion surrounds and holds the shouldered portion of the adjustingscrew in a tight and secure manner.

Patented Nox". 10, 1970 INVENTOR. MARTIN J. HERMANNS ATTORNEY HOLD DOWNAND RETURN CLIP AND ADJUSTING SCREW ASSEMBLY FOR PXVOTED LEVER CLUTCHESFriction clutches are widely used to drivingly connect a pair ofrelatively rotatable elements and usually includes a driving and drivenmember. In many spring loaded clutches, the driv ing member includes anannular pressure plate which is axially movable so that one of itssurfaces is operative as a friction surface and maybe brought intocontact with an annular friction surfaceofthe driven member therebyengaging the driven member with the driving member. Resilient means areutilized to cause the engagement of and to maintain driving contactbetween the friction surfaces. Quite often the disengaging meansprovided to .overcome the resilient means for disengagement of thefriction surfaces takes the form of a series of pivoted levers pivotallymounted relative to the driving member. These release levers, of course,compress the resilient means tothereby permit the pressure plate to cometo .a disengaged position; In order to insure movement of the annularpressure plate some for'mof connecting means must be provided betweenthe lever means and the pressure plate so as to drivingly'connect one tothe other. This connecting means,

in many clutch applications, has-taken the form of an adjusting screw.mounted on the pressureplate and a spring cliphaving a holddown andreturn function connected between the adjusting screw and aleverend;

On'e example'ofsuch an arrangement is found in the patent toThelandcr'USwPat. No; 2,724,475 issuedNov. 22, l955.ln the clutcharrangement shown in this patent the hold down and return clip takestheform of an elongated strip of flat 'sprin'g material bent soapproximately :an L-shape with one slotted legof the Lib'ein'g utilizedfor attachment to the headed end of theadjusti'ng screw. This leg alsoincludes lugs bent from its outerend' in spacedirelationship forabutment and location relative to the side of the headof the adjustingscrew. The use ofsuchzaspring clip,=however, necessitates carefulassembly of this hold down and return clip on the adjusting screw sincethe bent lugs may be'come misaligned and engage beneath the bolt headinste'adof surrounding it. Such misassembly operation resultsin anaddedcost to the clutch manufacture due 'tothe .factthat'the holddownand return clip must then be physically adjusted relative to itsoutermost proper position'to place *the spring c'lipin its proper loadtransferring position. Furthermore, the use of bent lugs or the springclip does not offerassecure a connection as'is desired. It would,

.therefore,-beadvantageous toprovide-aho'lddown and return clip v which.could -be easily zp'hysicallyassembled with the adjusting screw andwould also offer a secure connection therebetwe'en.

Accordingly, it -is an object-of'this invention to provide a hold downand :return clip and adjusting screwassembly wherein the hold down-andreturn' :clip'may be securely and positively: affixed to-theadjustingscrew.

derstood byktheraccompanying drawings, whichby way of iilustration' showa preferredaembodiment ofxthe invention and what is to be: consideredto'be the bestjmod e of applying the aboveiprinciples.

\ lnfthe drawings: t

FIG. 'l isajpartial) rearview of a clutch embodying this invention;

FIG. 2isasectional sideviewtakenorilines2-2 of FIG. 1;

is biased towards a friction disk by compression springs acting throughrelease levers carried by a back plate or housing member and pivotalrelative to the back plate or housing member about a pivot pin. Thecompression springs are seated at one of their ends in depressions inthe housing member and extend rearwardly therefrom to be seated at theiropposite ends in depressions formed in a series of release levers. Eachrelease lever has its pivot pin disposed intermediate its ends so thatthe. axially outer end of the release lever abuts against an adjustingscrew extending axially rearwardly from the pressure plate. A holddownand return clip having a general L'shape with a bent-over tab end ismounted on the adjusting screw so that the tab end engages the releaselever end. The opposite end of the hold down and return clip that formsone leg of the L-shape includes a slot which opens outwardly of the endof the leg so that the hold down and return clip may be slipped over theshank of the adjusting screw. A bore is also disposed in this leg of theL-shape, the slot portion terminating in this bore. This bore is oflarger dimension than the shank portion of the adjusting screw and ofsufficient dimension so as to be slidable over-ashoulder portion vof theadjusting screw, formed on the adjusting screw directly adjacent to itshead.

Referring nowto FIGS. 1 and 2, the clutch of the instant invention isshown in its engaged position and is indicated generallyat 10. itincludes an internally splined hub 12 which is adapted to be drivinglyconnected to a splined shaft which serves as the output of the clutch(not shown) and a driven member-or friction disk 14 which extendsradially from and is integrally and drivingly connected to thesplinedhub 12. The

driven member 14 base pair of annular friction faces 16, one beingsecured by a series of rivets 17 (only one shown) on one :axialside ofthedisk and the other being secured to the other plate 28. Pressureplate'28 is axially movable relative to the flywheel 22andtheback-plate24 and hasa plurality of rear wardly extending.circumferentially spacedlugs 30 which pro- 7 ject-through openings 32 provided in the back-plate24. Pressure plate 28, by this-arrangement, isconventionallyvdriven bythe back plate 24 by'means-of the lugs 30 drivingly engaging sides -34ofopenings 32 formed in the back plate or housing 24; r

The lugs 30areanintegral part of the pressure plate 28 and eachhas: anadjustingscrew 36 havinga head 37 and a shank portion 39 threaded inanaxially extending hole 38 provided in the lugs 30.0f the pressure plate.A lock nut 40 and a washer 41 are providedonthe shank of each screw 36to lock the screwinposition and-thereby provide a means for preliminaryadjusting of the axial position of the pressure plate 28 in aconventional manner.

Means" is providedfor axially moving the pressure plate 28 into and outof engagement with the driven member 14 which means is carried bythedriving member 18 and'comprises a plurality of release levers 42,each having an elongated radial .axis which is radially. disposedrelative to the axis of the pressure plate 28. Each oftherelease leversis pivoted by a pivot pin 4410 as to be mounted with the driving member18. This is accomplished by the pivot pins 44 being extended chordsllyrelative to the housing 24 and being secured at their opposite ends inopenings .46 in the housing or back plate 24 by means of flanges 48formed on their ends on the outside of the openings 46. The pivot pins44 are then received in spaced openings 49 in the release levers 42 sothat the latter are pivotally mounted to the back plate or housing 24.

Resilient spring means is provided to pivot the release levers 42 aboutthe pivot pins 44 so that, as viewed in FIG. 2, as each lever 42 ispivoted clockwise, a radially outer end 52 thereof will press against anexposed surface of the head 37 of the screw 36 and urge the pressureplate 28 towards the left and into engagement with the driven member 14.Each of the levers 42 extend radially inwardly from the pivot pin 44 andterminates at a radially inner end 56, which inner end is engaged on theright side thereof by the usual throwout bearing (not shown) which isoperative to pivot the same counterclockwise for release of the drivenmember 14.

Intermediate the ends 56 of each of the levers 42 and the pivot pin 44,a compression spring 54 operatively engages each of the levers 42 andbiases the same clockwise about the pivot pin 44 in a direction to biasthe pressure plate 28 inwardly against the driven member 14 through thecooperative action of the lever 42. The back plate or housing 24 has aplurality of circumferentially spaced reaction seats shown generally at58 in which the compression springs 54 seat at their inward ends.Pressure springs 54 extend axially and radially outwardly from the seats58 and in an angular relationship to the axis of the clutch so as toabut against projections 59 formed on each of the release levers 42 soas to be somewhat free to pivot thereon as the clutch 10 moves betweenengaged and disengaged osition. The clutch structure so far described isgenerally conventional and is shown, for example, in the patent toPhelps et al., U.S. Pat. No. 3,276,555 issued Oct. 4, 1966.

A spring clip 60 is provided to resiliently connect the head 37 of eachadjusting screw 36 with the hook-shaped radially outer end 52 of itscooperating release lever 42. Each spring clip 60 includes a bent-overtab portion providing a first portion 62 which hooks over the outer endof the release lever to provide the aforementioned resilient connection.The spring clip 60 is generally L-shaped in side view and cross sectionbeyond the bent-over tab portion 62 so as to provide a first leg 64which extends generally axially of the clutch and a second leg 66 whichextends generally perpendicular to the axis of the clutch. The secondleg 66 includes a slot 68 which opens outwardly of the end of the secondleg and extends linearly inwardly therefrom to merge with a bore 70 alsoformed in the second leg of the L-shape. The slot 68 is of sufficientdimension so as to be easily slidable over the shank portion 39 of theadjusting screw 36, while the bore 70 has a diameter of sufficient sizeto permit it to slide outwardly and encompass a shoulder portion 72formed immediately adjacent to the head 37 of the adjusting screw 36.Thus, the spring clip 60 may be easily assembled upon the adjustingscrew 36.

Assembly is accomplished in the following manner. The pressure plate 28and adjusting screws 36 and release levers 42 are mounted with thehousing 24 of the clutch. The spring clip 60 has its bent-over tabportion 62 placed in engagement with the radially outer end 52 ofrelease lever 42. The spring clip 60 is then deformed so as to clear thehead 37 of the adjusting screw and the slot 68 slid over the shankportion 39 of the adjusting screw. The bore 70 of the spring clip 50 iscentered relative to the shoulder portion 72 of the adjusting screw andpermitted to resiliently snap up against the inward surface of the head37 of the adjusting screw. The spring clip, adjusting screw and leverend are then disposed in assembled relationship.

in the foregoing description it is apparent that a hold down and returnclip and adjusting screw assembly for a pivoted lever clutch has beenprovided which makes for easy and sure assembly with its clutch andwhich forms a secure connection and yet is easily disassembled.

Though only a single embodiment of this invention has been shown anddescribed, it is understood that many changes maybe made therein withoutdeparting from the scope of the invention.

lclaim:

1. in a spring loaded clutch having an axial extent, the combinationcomprising:

a. a pressure plate;

b. a clutch lever having a bent end at its radially outer extent;

c. lug means on said pressure plate extending axially outwardlytherefrom;

d. adjustable screw means threadably inserted in and extending axiallyoutwardly from said lug means;

c. said adjustable screw means including,

1. a headed end;

2. a shouldered portion disposed immediately forwardly of said headedend; and

3. a shank portion integrally connected to said shouldered portion andof smaller diameter than said shouldered portion;

f. a hold down and return clip means disposed between and attached tosaid adjustable screw means and said bent end of said lever;

g. said hold down and return clip means being of a resilient materialand shaped so as to provide a bent tab portion and an L-shaped portionintegrally attached thereto, with first and second leg portions beingformed by said L- shape;

h. said bent tab portion engaging said bent end of said lever forproviding a connection therebetween;

i. said first leg of said L-shape of said hold down and return clipmeans extending from said bent tab portion in an axial direction;

j. said second leg of said L-shape of said hold down and return clipmeans extending radially inwardly from said first leg; and

k. said second leg of said L-shape having a slot extending to the radialinward termination of said second leg and merging outwardly thereof witha bore portion disposed in said second leg, said slotted portion beingof slightly greater dimension than said shank portion of said adjustablescrew and of smaller dimension than said shouldered portion and saidbore portion being of slightly greater diameter than said shoulderedportion of said adjustable screw, whereby said hold down and return clipmeans is easily assembled in secure relationship with said clutch leverand said adjusting screw.

2. The combination set out in claim 1 wherein said spring loaded clutchincludes:

a. a housing; and

b. a spring means extending angularly outwardly from said housing forengaging said clutch lever.

3. The combination set out in claim 2 wherein said spring loaded clutchincludes a friction disk and a pressure element and said friction diskis engaged between said pressure plate and said pressure element whensaid clutch is engaged.

4. in a clutch having a driving member, a housing rigidly connected tosaid driving member, a driven member disposed intermediate said drivingmember and said housing member and adjacent to said driving member, apressure plate disposed intermediate said driven member and saidhousing, said pressure plate having a series of lugs extending throughapertures in said housing, adjusting screws having a threaded shankportion and a head portion, said adjusting screws threadably engagingeach of said lugs, release levers pivotally connected intermediate theirends to said housing and arranged to have one free end bearing againstan adjusting screw, spring means for resiliently biasing said releaselevers against said adjusting screws, and clip means for maintainingsaid adjusting screws and release levers in operative engagement, theimprovement comprising a shoulder on each of said adjusting screwsdisposed intermediate said shank portion and said head portion andhaving a greater diameter than said shank portion, and said clip meanscomprising a spring clip formed of resilient material and shaped toprovide a bent tab portion and an integral L-shaped portion, saidL-shaped portion having first and second leg portions, said bent tabportion adapted to interengage said one end of said release lever, saidfirst leg and of smaller dimension than said shoulderQand said borebeing of slightly greater diameter than said shoulder, whereby .saidspring clip may be assembled over said shank portion and locked intoengagement with said shoulder portion.

